Rotary engine



3 Sheets-Sheet 1.

(No Model.)

A @Bomv ROTARY ENGINE.

No.. 498,618. Patented May 3o, 1893.

TH: Nonms varias co., Pnoruuvlqmymsnmn'ms. D. c.

(No Model.)

3, D Y 0 B A RQTARY ENGINE. No. 498,618.

Patented May 30, 1893.

Fi El.

(No'ModeI.) 3 Sheets-Sheet 3.

A. BOYD. ROTARY ENGINE.

Patented May 30 l IIIIIIiIIIIIHI imm TH: Noam; PETERS co, PHmoMmmwAsmNnToN. n. c.

s UNITED STATES PATENT OFFICE.

ARTHUR BOYD, OF MIDDLESBROUGH, ENGLAND.

ROTARY ENGINE.`

SPECIFICATION forming part of Letters Patent No. 498,618, dated May 30, 1893. Application tiled November 7, 1892. Serial No. 451,278. (No model.) Patented in England February 13, 1892,11'6. 2.820. y

To all whom it may concern:

Be it known that I, ARTHUR BOYD, a subject of the Queen of Great Britain, residing at Middlesbrough, in the county of York, England, have invented certain new and useful.

a high speed rotary engine capable of `work-`A ing smoothly on the single-acting principle, having constant surface contact between the driving cylinder and resistance pistons and in which the defect of line contact is overcome and running pistons over ports is oloviated, as well as the disadvantage of having delicately adj usted working parts inaccessible whether the engine is in4 motion or at rest.

A further object of my invention is to so combine and arrange the moving parts and provide for the admission, distribution and exhaust of the steam or other actuating medium that the moving parts are balancedrunder the varying pressures whereby the packing is not subject to undue wear, and the energy of the actuating medium is so disposed that the engine is free from shocks and variations of speed when running, theV heavy parts having a uniform angular velocity.

Further advantages derived from the improvements constituting my invention are that the engine can be constructed to work as Y a simple or compound engine, is reversible and can be readily turned o the dead center when required to start the engine without moving the main shaft and its load.

In the accompanying drawings I illustrate my invent-ion as applied to both a simple and a compound single-acting engine, and show separately some of the parts all designed for working in the horizontal position from which it will be readily understood how the engine can be modified inv design to Work in the vertical or inclined position if sorequired.

In the drawings in which corresponding parts are designated by corresponding marks of reference-Figure 1 is a central longitudinal vertical section of a single acting simple engine constructed in accordance with my invention. Figs. 2 and 3 are vertical transverse sections on lines fc, and y y, respectively thereof. Fig. 4 is a detail view, showing the inlet and exhaust ports c, and k2. Fig. 5 is a central longitudinal vertical section of a compound engine constructed in accordance with this invention. Fig. 6 is vertical transverse section taken on lines y y of Fig. 5,'showing a modified form of construction of the cylinder. Fig. 7 is a transverse vertical section on line z a' of Fig. 5.

. I will first proceed to describe my invention as applied to a single-'acting simple engine. a is'the main shaft, the rotary motion of which isthe power of the engine to be utilized. In this case the main shaft ais made hollow for the reception of the shaft Z2 which is employed in connection with certain movv ing parts of the engine inthe manner hereinafter described and which for distinction I will term the resistance shaft.y These two shafts are iitted or coupled together to revolvein line with relatively different rotary motions. The cylinderc and its covers c c2 are secured axially to and rotate with the main or driving Vshaft. a, their, combined weight serving as a lliywheel to the engine. The resistance shaft b rotating within the main shaft a is furnished within the cylinder with a drum or barrel d. The annular space thus formed is occupied by radial longitudinal walls or partitions e e2 projecting as xtures from the cylinder to work against the l drum and which are the working pistons of the engine, between which are other interme- IOO any pressure which may be set up against the pistons, 'n.2 being relief ports to reduce such pressure to a minimum.

A convenient form of mounting the cylinder c, and the main shaft a with their accessory moving parts is shown in the drawings, and consists of a cylindrical casing g with end covers g g', erected on a bedplate h and forming a chamber in which the cylinder c revolves.

k is the port in the cylinder cover which is shown in Fig. l exactly opposite to the inlet port 7c', 7a2 being the outlet port. The relative positions and areas ofl these ports as they appear in the face of the cover g are shown in Fig. 4C.

For structural compactness the casing g is preferably constructed concentrically4 with the cylinder c and main shaft a, and is furnished with the usual glands, packings, and

metal bearings required in high speed steam engines including a gland spring s for holding' the cylinder face up to its work, which gland spring is dispensed with when the steam is supplied into the casing through the aperture la in the head thereof, as is shown in dotted lilies in Fig. 1, when the steam pressure behind the cylinder cover c2 serves the same purpose.

h h2 are standards erected on the engine bed plate-h, oflwhich 71. is simply furnished with bearings for the tail end of the main shaft a., while h2 is specially constructed for the reception of the eccentric Z, by which to adjustthe relative leverage and movements ofthe links and levers m', m2, m3 and m4 which are shown in Fig. 3, by which the lead, cut off, exhaust and compression of the steam are regulated and controlled and the engine reversed and for which purpose an index j and pointer t7'2 arer useful When provided in the position shown. In practice the parts being constructed and arranged as shown and described, they are intended to operate as follows:-VThe engine having been adjusted on its axisby turning the Wheel n if necessary so-that the pistons are in the starting position as shown in Fig. 2, the steam enters the spacebet-ween the pistons e f and through i the eect of the steam so admitted is to force the pistons e and e2 from their companion pistons f f2 as far as possible, and that the pressure of steam on both pistons in each case is necessarily equal and the cylinder in pressure balance, but in order to obtainuseful Work from the steam, the equal pressures on the said pistons do not meet with equal resistance, that is to say that the steam pressure during admission andA expansion meets with a lower resistance from the pistons e e2, which are the working pistons, than from the pistons ff2, which are the resistance pistons. Upon this differential piston resistance depends the efficiency of the engine and the special combination or arrangement of parts by which itr is brought into elfect constitutes animportant part of my invention which l Will now proceed to describe, and which is illustrated in section in Fig. l with a corresponding transverse view in Fig. 3.

The disk In is keyed to the main shaft a and is made heavy enough and properly balanced'to serve as a flywheel.

mm2 m8 and m4 constitute a system of links and leversarranged and adjusted to operate in combination with the shafts a and b, so that while the steam imparts a uniform angular velocity to the pistons e and e2 and therefore to the cylinder c and main shaft 0L, the resistance shaft b revolves with a varying velocity corresponding to the variations of space between the pistons f f2 and the pistons e e2 as steam is admitted, expanded and exhausted within the engine cylinder. The pin p is secured to the disk wheel n and is therefore directly connected like a crank pin to the main shaft @,the pin p2 is similarly directly connected through the lever m3 to the resistance shaft b, the link m being in constant compression andthe link m4 in constant tension when theengine is going ahead as shown by the arrows in the gures, andwhen the engine is `running in the opposite direction. The controlling shaft 0 is placed eccentrically to the axis of the main shaft a, round which it can be moved ata constant radius in the stand h2. The pins p p2 are coupled together by the system of links m', m4, and cross lever m2, as shown more particularly invFig. 3. Taking this system of levers and links as shown in Fig. 3 to represent a position of the pistons at which the steam is giving out'work, it will be seen that pressure of steam upon the pistons e e2 which is transmitted to the pin p has mechanical advantage over the pressure of steam' upon the pistons f f2 which is'translnitted to pin p2, and that as the system of links revolves this mechanical advantage reaches the vanishing point, and is then transferred to the pistons f f2 for the remainder of the revolution of the main shaft, after which it reverts to the pistons e e2 as before for the like part of another revolution, thus passing through two vanishing or neutral points in each revolution, which neutral points are the dead centers of the engine. In that part of a revolutionthrough which the mechanical advantage is with the pin p', that is with the pistons e c2, the steam is entering into and expanding within the steam spaces of the cylinder by driving the working pistons e e2 in advance of the resistance pistons ff2, and in the remaining part of the revolution in which the mechanical advantage is against the pin p', the exhaust steam is being swept out of the cylinder by the pistons f f3 advancing or closing up to the pistons e e2, that is to-say the resistance pistons f f2 have a reciprocal motion relatively to the working pistons c. e? as they all revolve together, the said' pistons e e2 nevertheless having a uniform 'angular velocity which is accordingly transmitted to the main shaftct.

The eccentric Z is journaled in the standard h2 inline with the shaft a, and has upon the rear of the periphery a worm wheel g', engaging with the worm Q2, by the rotation of which the eccentric cam Z itself will be rotated, the eccentric having eccentrically thereina shaft o upon the end of which is mounted the hereinbefore described linkA m2, the said shaft'o being carried by the rotation of the eccentric around the axial line of the main shaft a, the said eccentric thus serving as a means for changing the angular position of the controlling shaft 0, thereby moving the pin p2 with its lever m3 and therefore the pistonsfvf2 wi-thout moving the main crank pin p', the engine being in consequence either altered in' grade or expansion, or reversed as shown by the pointer. This can be done when the engine is going.

The wholeengine is in'mechanical balance by means of counter balances for'which purpose the lever m3 has the slotted extensie shown in Fig. 3.

Having now described a single-acting simple engine complete in all its parts as constructed according to my invention, I will now proceed to describe Figs. 5 to 7 inclusive which illustrate my invention as applied to a com pound engine. In order to compound the engine, I add to the steam cylinder c the part c3 divided therefrom by the intermediate partition c4. .Taking o as the high and c3 as the low pressure cylinders respectively, their relative capacities can be obviously adjusted to suit any conditions withinH practical limits under which the steam is to be expanded, and in Fig. the capacities of these cylinders are shown in the proportion of about three to'one. The steam exhaustedfrom the high pressure cylinder c passes through the pipe r into ay receiver r, from which it is delivered through the; admission pipe r2 into the low pressure cylinder c3; In other respects my invention involves no essential differences in the arrangement of parts or combination of details suitable to either a simple or compound singleacting engine, the relative action of the pistons under steam pressure in combination with a main and resistance shaft being pre-l cisely similar in either case. The .modifications of the arrangement of parts for admitting and clearing the steam from the cylinder or the precise means for adjusting the piston. resistance in the manner as hereinbefore deing the same-piston resistance against the steam as has alreadybeen described withreference to the system of links shown more particularly in Fig. 3. Figs. 5 and 7 however illustrate a modified arrangement of the ports for admitting and clearing the steam from the cylinder which is thought to have practical advantages such as small surface friction. In this modification the valve consists o f a cylindrical casin g n, inclosing an annular space 1a4 round the main shaft a., which casing is flanged up to the cylinder cover, the ports 1t of which lead direct from the annular space 154 to the cylinder steam space. n is the valve liner which screws into the .casing cover g', and can be screwed round by thelevert to any position Whether for adjusting the cut off of the steam, stopping or reversing the engine, the proper positions for which are marked on the index js. In order to effect-its purpose the valve and its connections are furnished with the following arrangement of ports. f

Referring 'more particularly to Fig.- 7, 155 is the port in the valve o which passes over the ports k6' and 157 in the valve liner -v tothe inlet and outlet ports 1c k2 inl the casingcoverg', which take the form shown in Fig. 7 to admit of the valve liner ports 166107 being set to different positions as required. The above engine serves all the purposes of the angular adjustment of the controlling shafto, except that if the shaft o is fixedk in position,the engine caunotbe turned off the dead center Without moving the main shaft and itsv load.

IIO

Therefore all provision for moving the shaft v o as described with reference to Fig. 1 is omitted in Fig. 5.

When the engineis going ahead as shown by the arrows in Figs. 2, 3 and 6, thesteam acts directly on the working pistons e c2, the reaction being sustained by the resistance pistons ff2, and the uniform angular velocity of the main shaft ct is converted into the variable velocity of the lresistance shaft b;

but when the engine is reversecLff2 become the working pistons and e e2 the. resistance pistons and the variable angular velocity of the resistance shaft bis converted into the uniform angular velocity of the main shaft a.

By constructing the cylinder inthe manner'.

shown in Fig. 6, in which asis a detachable IZO part with the piston e2, the interior of the cylinder is made easily accessible for inspec tion and repair.

Having thus fully described my said invention and the manner of performing the same, I wish it to be understood that I am aware that the method or principle of obtaining useful work from steam by the differential resistance of revolving pistons is not new. I

therefore make no claim to such method or principle otherwise than asembodied in and carried into practice by myimprovements as vabove specified.

What I claim, andv desire to secure by Letters Patent, is-

1. In a rotary steam engine, the combination with two concentric shafts, of a driving cylinder' having pistons attached thereto, secured upon one of the said shafts, pistons secured upon the other shaft and contained within the said cylinder, a crank lever connected to one of the said shafts and a fly wheel mounted upon the other shaft, a link eccentrically pivoted in respect to the said shafts, and links connecting its opposite ends with the saidfly wheel and lever, substantiallyias described.

2. In a rotary steam engine, the combination with two concentric shafts, of a driving cylinder having pistons attached thereto secured to one of the said shafts, pistons secured to the other shaft and contained within the said cylinder, a shaft adapted to be rotated around the said shafts and alink pivoted thereon and having its opposite ends connected to the said first-named shafts, substantially as described.

3. In a rotary steam engine, the combina` tion with two concentric shafts, of a driving Ycylinder having pistons attached thereto secured to one of the said shafts, pistons secured rto the other shaft and contained within the said cylinder, a fly wheel secured to one of the said shafts and a leversecured to the other shaft, a shaft adapted to'Y be moved around the said shafts, a link mounted thereon, and links connecting the opposite ends of" the said first namedlink with the said fly wheel and lever, substantially as described.

L In a rotary steam engine, the combina tion with two concentric shafts of a drivin-gl y cylinder having pistons attached thereto se- `other shaft, an eccentric jonrnaled in line with the said shafts and having ashaft eccentrically mounted therein, means for rotating the said eccentric, a link journaled on the shaft in the eccentric, and links connecting its ends with the said fly-wh eel and lever, substantially as described.

6. In a rotary steam engine, the combination with a main shaft having a cylinder and a flywheel thereon, the cylinder having pistons secured thereto and a steam port therein, of a resistance yshaft concentric to the said main shaft and having a lever and vpistons thereon, the said pistons being contained within the said cylinder the said resistance shaft having ports passing diametrically through the said shaft Within the said cylinder, a cylindrical casing inclosing the said cylinder and having induction and eduction ports therein, and a link eccentrically pivoted in respect to the said shafts and having its ends secured to the said flywheel and lever, substantially as described.

7. In a'rotary steam engine, the combination with` two concentric shafts, of a driving cylinder having pistons attached thereto secured to one of the said shafts, pistons secured tothe other shaft and contained Within the said cylinder, an eccentric journaled in line with the said shafts, and having a pinion secured thereto, a worm yshaft gearing with the said pinion, a shaft eccentrically mounted on the said'eccentric and a link journaled on theshaft on the said eccentric and having its opposite ends connected with the first named shafts, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR BOYD.

Witnesses: n

GEORGE JAMES CLARKsoN, EDWARD THOMAS ELcoAT. 

